Materials handling process and apparatus



Dec. 16, 1958 F. H. MORK 2,864,561

MATERIALS HANDLING PROCESS AND APPARATUS Filed Jan. 10, 1952 2 Sheets-Sheet l I N VE NTOR Fred H. Mar/r ATTORNEY F. H. MORK Dec. 16, 1958 MATERIALS HANDLING PROCESS AND APPARATUS 2 Sheets-Sheet 2 Filed Jan. 10, 1952 IOIZ INVENTOR Fred H. Mar/r BY WW W' ATTORNEY United States Patent HANDLING PROCESS AND APPARA MATERIALS This invention relates to a new design material feeder for portable crushing and screening plants, and also includes a method of feeding material to a plant of this type.

For at least the past twenty years, material has been fed to portable crushing and screening plants in much the same manner. The material to be processed is conveyed by a main conveyor to a main screen which separates the materials to be crushed from that which is already sufiiciently small in particle size. This main screen structure may also separate the largest material which must be acted upon by a jaw crusher from the smaller material which may be crushed by a roll crusher. After crushing, the product is returned to the mainconveyor and returned to the main screen.

At the present time the capacity of a typical portable crushing and screening plant is ninety to one hundred and twenty cubic yards per hour of three-quarter inch material, based on an average of twenty-five percent crushing. The main screen (a four by ten foot two and onehalf deck vibrating screen) has a capacity of one hundred twenty to one hundred forty cubic yards per hour. The ten by thirty-six inch jaw crusher handles forty-three to fifty-eight cubic yards per hour. The thirty by eighteen inch roll crusher handles fifty cubic yards per hour.

Some material crushed by the jaw crusher must also be crushed by the roll crusher in order to have the entire volume pass the smallest screen of the main screen unit. For the purpose of illustration, this finished size screen is considered to be of three-quarter inch size, as this size material is most commonly used for maintenance and construction of secondary roads. It is generally conceded that, with the gradation in the pit being most irregular, the production of the two crushers to obtain three quarter inch material would be at least sixty cubic yards per hour and could be one hundred cubic yards per hour with the gradation in the pit exceptionally adaptable to the crushers. The amount of material crushed is more dependent upon the ability of the main screen to sort the incoming material than upon the ability of the crush ers to crush the sorted materials.

An object of the present invention lies in the method of pre-grading the material and introducing the smaller particles which are already of proper size directly into the surge bin or under screen hopper at the outlet of the machine. As the average material processed contains seventy-five percent of material of proper finished size, only twenty-five percent of the material would be introduced on the main screen, thus greatly speeding the sep aration, and increasing the capacity of the plant up to four hundred percent. Thus from two hundred forty to four hundred cubic yards per hour could be processed.

A feature of the present invention lies in the provision of a feeder for use with portable crushing and screening plants which includes a grizzly or screen capable of separating the material of proper finished size from the material which must be crushed. Only this material which requires crushing, together with any small amount ice of smaller material which clings to the larger pieces due to moisture or lack of crushing need be introduced on the main screen of the portable plant. The finished size material is introduced directly to the surge bin or under screen hopper. Because of the large screen area on the main screen, and the pre-plant separation, the small material entering the plant with the material to be crushed is readily separated therefrom.

In moving portable plants of this type to a new or different situs, it is frequently necessary that the equipment be transported over public highways. As is well known,

various states have passed laws imposing maximum load limits per axle which may not be exceeded. While weight limits tend to preserve the highways, nevertheless such limits present serious difficulties with respect to heavy machinery. Where large scale crushing and screening operations must be efliciently performed, the aforesaid laws have been an especial detriment and handicap.

In portable crushing and screening plants it is'usual practice to recirculate the crushed material to the main screen until the crushed material passes through the screen. The crushed material is deposited onto the receiving conveyor with the incoming material, and is handled therewith.

One of the most crucial difliculties encountered with an arrangement of the foregoing character is that for a given handling rate, the conveying and screening devices must be designed to handle the maximum amount of material which constitutes the output rate. be appreciated that the receiving conveyor must transport a quantityof material per unit of time which is equal to the average output plus whatever material is recirculated via the crushers. Not only is the above true, but the screening mechanism must be similarly designed to withstand such amounts.

Accordingly, one important object of my invention is to employ an auxiliary vibrating screen or sifting device with a pair of superimposed auxiliary conveyors or chutes, the purpose of which auxiliary equipment is to effect an initial separation of the material. From actual experience, I have discovered that, in'certain specific cases, sixty to ninety percent of the material to be processed may be diverted from the conveying and screening apparatus contained on the portable unit. Under these average conditions, which incidentally may diifer .inin:

dividual and specific instances, only ten to forty percent Another object of the invention is to effect a concomitant reduction in the manufacturing cost of the portable unit Where the volume of material handled remains the same. 1

Still another object is to secure the preceding desirable aims without the use of specially designed equipment, the basic auxiliary equipment envisaged by the invention usually being available at or near the mine or quarry which basic equipment is easily adapted for use with the portable unit.

Other and further important objects and advantages of this invention will be apparent from the following description taken in connection with the drawings forming a part of the specification and in which:

Figure l is a schematic elevational view of the apparatus forming the subject matter of my invention, the view showing one side of the auxiliary equipment and one end of the portable crushing and screening unit,

' Figure 2 is a schematic view taken in a direction nor- For example, it will mal to that of Figure 1, showing one side of the portable unit and its contained apparatus.

Figure 3 is a view similarto Figure 1 showing a modified arrangementt of :apparatus.

Figure 4 is a diagram of-the process employed in feeding the material to be crushed. and screened, .during processing thereof.

. Referring now to the drawings, it will be observed that in practice a complete processing ,operation may rbe carried out with the following equipment: A material loader A, auxiliary apparatus-B, azportable unit C and a hauling vehicle D.

The .material loadingstation ,-A represented ;for..the purpose of illustration aswa Ffeed hopper .10:.covered by a scalping grizzly ;11, supplies.lthe auxiliary equipment B with the raw material.12;which;material may comprise gravel, ore .or. the like, :theiproducts of which are to be of anpultimatepredeterrninedimaximum size. It will be understood that the raw .material .12 includes 1 particles that are undesirably'large. T'herefore,. my auxiliary apparatus B includesavibrating screen 14, grizzly, or similar separating device which is of a mesh sufficient to pass that portion of the material 12 which is already of the proper ,dimension. Accordingly, the material passing through the single deck screen or gizzly 14 bears the reference numeral 16, this material 16 falling into a chute 18. The material which is too large to pass through the inclined screen-14-is labeled 20 and is directed into a secondchute 22. The screen 14 is vibrated in any one of several knownways, as by-an electric motor 24, to effect'the above mentioned separation of the material 12 into its component parts 16 and 20.

The material thus separated is'received by a pair of conveyors 26 and 28, 'thematerial 20 being directed on the conveyor 26 and thematerial 16 being directed on the conveyor 28 through the respective chutes 22 and 18. The conveyors 26 and 28 may be of any desired type and as shown include endless belts 30 and 32 trained over driving pulleys 34 and 36, a motor 38 serving as the driving means for both of thebelts 30 and 32 in their depicted superposed relationship. A suitableframe work 40 supports the belts 30 and 32 by means of the idler rolls 42 and 44. The framework 40 is in turn held at a preferred inclination by a pair of spaced standards 46 and 48. The screen 14 and the conveyors 26, 28, along with their associated and enumerated elements, constitute what has been termed the auxiliary apparatus or equipment B. p

The portable unit or plant C is rendered readily movable by a plurality of wheels 50 and contains a chute 52 which the material 20 is fed into from the conveyor 26, the chute 52 discharging onto an inclined double decked vibrating screen 54 provided with upper and lower screen elements 56 and 58. Positioned beneath the screen 58 is a hopper 60 into which the material passing through the lower element 58 falls and is collected. As will .presently .bemade more apparent,the lower element 58 is approximately of the same mesh as the screen 14. An additional screen 57 ispositioned'below screen 58, substantially in alignment beneath chute 52 to separate fines from part of the troughs from screen 58 which are discharged separately by chute 59 into side conveyor 61.

The upper screen element 56 is of a mesh such as to pass that part of the material 20 which is of a size to be adequately accommodated by a double roll crusher 62, this material being designated by the reference numeral 64.which material is shifted from the upper side of the lower screen element'58 to a chute 66 leading to the crusher 62. That portion of the material 20 remaining on the .upper screen element 56 is given the numeral 68 and itis directed to a jaw crusher 70 via a chute 72.

The two .crushers 62 and 70 break up the respective material 64 and 72 to a size within their inherent capabilities andthe crushed, material thusformed is commingled together to form material 74 and permitted to fall onto a relatively short conveyor 76 which conveys this commingled material 74 to a rotary elevator 78 provided with a series of flights 80. The elevator 78 lifts the material 74 onto another relatively long conveyor 82 which extends substantially the entire length of the unit C, the conveyor 82 discharging the material 74, which has now been crushed, onto:the,upper-series element 56. The material 74 in this way becomes intermixed momentarily with fresh iucomingmaterial 20,- and it will'be understood that that'part oftheqnaterial 74 which is now small enough to pass through the upper screen element 56 will do so, still further passage thereof being effected through the lower element 58 of that portion which has been sufiiciently crushed to be sifted by the screen 58. While there is a continual intermixture of new incoming. material 20 with the crushed material 74, it will be appreciated that thereis alsoa-continuous separating or sitting out-ofcrushed material" that is of'the desired maximum size.

Consideringnow the material 16'being transported over the conveyor 28, it will be, realized that this material 16 is of the desired maximum size, having been screened by thescreen 14, and that no further sifting is required. Accordingly, this. material 16is discharged into a chute 84ileading directly to the hopper 60 where it is intermixed falling-from the screen element 58 to produce the final product'86, which final material has now beenreduced to the proper maximum size. The chute 84 is omitted in Figure 2 of the drawings. In normal operation the material in the hopper 60 is only temporarily stored therein, there being a continuous removal of this stored material '86 by way of still. another conveyor -88. The conveyor 88 mayv discharge into the haulingvehicle D, illustrated as a truck 90.

In brief, the course that the original varied size material takes is as follows: The varied size material 12 is separated into the material 16 and 20. In that the material 16 is of the proper maximum size it is sent directly to the hopper 60. While the material 20 is too large to pass the screen14, some of it will pass the upper screen element 56 and has been designated as material 64. The part of the material 20 not passing the element 56 bears the reference numeral 68. After the materials 64 and 68 have been crushed they are recombined and have been given the reference numeral 74, since their physical state has been changed. The material 74 is dumped back on the element 56 along with newly arriving material 20 and those particles that will pass the element 56 willthen do so and those particles small enough to passthe screen element 58 will continue their downward path into the hopper 60 from whence the material is removed as the final product 86.

In view of the fact that the material 16, forming part ofthe final product 86, does not pass over any of the conveyors 76, 78 or 82 noris handled by the screen unit 54, it will be-apparent that the material load that must be handled by the portableplant C has been considerably reduced, an average figure being 60% to 90% as stated in the early part of this specification.

From a different standpoint, it is apparent that a plant of given size and capacity can handle several timesrnore materialthrough my feeding method and apparatus, in view of the stepof by-passing the finished size material directly to the surge bin or finished material storage bin.

In Figure 3 I disclose a-modified form of arrangement. This structure does not have all of the advantages of the arrangement previously described, but is desirable where screening equipment is already available. The apparatus includes a portable plant C identical to that previously described. The plant C includes the inlet chute 52 designed to receive the larger material and a chute 84 now employed.

designed to accommodate the smaller finished size of material.

A scaffold 92 supports a vibrating screen or grizzly 94 capable of separating the material of finished size from the larger material which require crushing. A chute 96 directs the finished size material into the chute 84 leading to the under screen material hopper or surge bin. A second chute 98 directs the larger material into the overscreen material chute 52. A single conveyor 100, or any other similar device is provided for directing the material onto the screen 94.

Figure 4 shows diagrammatically the system or method Numeral 102 designates the supply, which is directed onto a vibrating screen or grizzly 104 capable of separating the finished material from that which must be crushed. The smaller material passes directly to the surge bin, storage bin or under-screen hopper 106. The larger material is directed to the main screen 103 of the portable crushing and screening plant.

The material is graded in the screening unit 108, the larger sizes being directed to the jaw crusher 112 and the roll crusher 114. After crushing, the product is directed to the main conveyor 116. which recirculates it to the main screening 108. This recirculation continues until all of the crushed material passes through the screen 108 and to the under screen hopper or surge bin 106.

From the diagram, it will be noted that the feeding of the material differs from previous methods. Rather than having the material go directly to the main conveyor leading to the main screen unit 108, this material is first passed through a screen or grizzly, and only perhaps onefourth of the material is screened in the portable unit.

In accordance with the patent statutes, I have described the principles of construction and operation of my material handling apparatus, and while I have endeavored to set forth the best embodiment thereof, I desire to have it understood that obvious changes may be made within the scope of the following claims without departing from the spirit of my invention.

1 claim:

1. In material handling apparatus of the class described, screen means, first and second endless conveying means, means for directing the material passing through said screen means to said first conveying means, means for directing the coarser remaining material to said second conveying means, second screen means associated with said second conveying means, said second screen means being positioned for the reception of material delivered by said second conveying means, a hopper beneath said second screen means, said first conveying means bypassing said second screen means and discharging directly into said hopper, crushing means associated with said second screen means for receiving material not passing through said second screen means, and conveying means leading from said crushing means to said second screen means for conveying the crushed material onto said second screen means.

2. In material handling apparatus of the class described,

inclined screen means, first and second endless conveying means, said first conveying means being disposed for the reception of material passing through said screen means and said second conveying means being disposed for the reception of the coarser material not passing through said screen means, second and third inclined screen means positioned one above the other, a hopper beneath said third screen means, the first conveying means bypassing said second and third screen means and discharging directly into said hopper and said second conveying means discharging onto said second screen means, first crusher means for crushing the material not passing through said second screen means, second crusher means for crushing the material not passing through said third screen means, and conveying means for receiving the crushed material from said first and second crusher means and discharging said crushed material onto said second screen means.

3. In combination with a portable material handling, crushing and screening plant provided with screening means, crusher means associated with said screening means, conveyor means for conveying the crushed material to said screening means, and a hopper disposed beneath the said screening means, the combination comprising a separable unit including auxiliary first and second conveyor means, said first auxiliary conveyor means discharging directly into said hopper and said second auxiliary conveyor means discharging onto said screen means, and auxiliary screen means positioned so as to discharge screened material onto said first auxiliary conveyor means and unscreened material onto said second auxiliary conveyor means.

4. A method of producing crushed aggregate, including the steps of screening the aggregate, conveying the material passing through the screen, collecting the conveyed material, separately conveying the material not passing through the screen, grading the last mentioned conveyed material, crushing the graded material, re-screening the crushed material, the material passing through the screen in the re-screening process joining the collected material.

References Cited in the file of this patent UNITED STATES PATENTS 1,476,880 Earle Dec. 11, 1923 1,525,450 Kneebone Feb. 10, 1925 1,611,026 Gustafson Dec. 14, 1926 1,611,128 Gunnison Dec. 14, 1926 1,618,721 Norman Feb. 22, 1927 1,859,560 Hartshorn May 24, 1932 2,020,800 Royer Nov. 12, 1935 2,210,093 Morrisay Aug. 6, 1940 2,276,333 Ovestrud Mar. 17, 1942 2,325,719 Turner Aug. 3, 1943 2,567,389 MacDonald Sept. 11, 1951 2,593,353 Shelton Apr. 15, 1952 OTHER REFERENCES One-Unit Crushing and Screening Plant Rock Products, October 1944, pages and 61. 

